Clone non-owned default core materials before editing

Clone default core materials so you get owned entries you can edit, optionally in bulk and with prices.

1. Default core materials in the admin library are non-owned and cannot be edited directly.

   ✓ 2026年10月9日に製品で確認済み

2. Cloning can be done in bulk across groups.

   ✓ 2026年10月12日に製品で確認済み

3. Prices can be cloned along with the material.

   ✓ 2026年10月12日に製品で確認済み

4. Only owned (cloned) entries become editable.

   ✓ 2026年10月9日に製品で確認済み